An assembly method of a negative-clearance three-row roller variable-pitch bearing

Abstract

The application discloses an assembling method of a negative-clearance three-row roller variable-pitch bearing, which comprises the following steps: (1) determining a target heating expansion amount of a first outer ring; (2) wrapping a heating belt on an outer circular surface of the first outer ring, contacting a plurality of dial indicators with radial rolling ways of the first outer ring, and measuring and calculating the heating expansion amount Delta d of the first outer ring during heating; (3) adhering radial rollers and radial retainers on the radial rolling ways of an inner ring by using lubricating grease; (4) after the heating expansion amount reaches a standard, quickly assembling first axial rollers and first axial retainers on first axial rolling ways of the first outer ring; (5) hoisting the inner ring with the assembled radial rollers and radial retainers into the first outer ring; (6) assembling second axial rollers and second axial retainers into second axial rolling ways of a second outer ring; and (7) installing O-shaped sealing rings on the second outer ring by using the lubricating grease; then, the second outer ring and the first outer ring are butted and fixed, and sealing rings at the end of the bearing are installed. The application can realize the hot assembly of the bearing, and has the characteristics of safety, effectiveness, simplicity and practicability.

Description

Technical Field

[0001] The invention belongs to the technical field of bearing assembly application, and particularly relates to an assembly method of a negative clearance three-row roller pitch bearing. Background Art

[0002] As the power of wind turbines increases, the load on the pitch bearings also increases. The pitch bearings of large-megawatt wind turbines have changed from the traditional double-row four-point contact ball structure to a three-row roller structure. Figure 1 As shown in the figure, this type of three-row roller pitch bearing is large in size, usually with an outer ring diameter exceeding 3 meters and a weight exceeding 1.5 tons. The following difficulties exist in assembling this bearing:

[0003] ① To ensure that the friction torque of the variable pitch bearing meets the requirements, the radial raceway of the three-row roller variable pitch bearing has a negative clearance, and the clearance value is generally less than -0.15mm. In addition, the radial raceway of the inner ring 1 is smaller than the outer diameter of the inner ring. It is difficult to install the radial roller 7 between the radial raceways of the inner and outer rings according to the conventional assembly machine press-fitting method.

[0004] ② If thermal assembly is used, the bearing heating temperature must not exceed 100°C to prevent excessive heating temperatures from damaging the retaining frame and the first and second O-rings 13 and 14. The first outer ring 4 expands slightly during heating, so the expansion must be measured quickly before assembly. Otherwise, the first outer ring 4 will lose temperature and cool, causing the expansion to decrease and making assembly impossible. Heating is typically performed in a pit-type tempering furnace, requiring personnel to enter the furnace for hoisting, which poses a safety hazard. Furthermore, the furnace is not located in the assembly area. After heating, the raceway diameter is measured with an inside micrometer. The hoisting and measurement process takes a long time, causing the ring to lose temperature, resulting in a smaller raceway diameter and making it difficult to successfully assemble the bearing.

[0005] ③ The radial retainer 6 is a segmented structure. When the radial rollers 7 and the radial retainer 6 are assembled, the radial rollers 7 and the radial retainer 6 are likely to fall off the radial raceway of the inner ring 1.

[0006] ④ When assembling the first O-ring 13 and the second O-ring 14 on the end face of the second outer ring 9, the O-ring sealing groove on the end face of the second outer ring 9 faces downward, and the two O-rings are easy to fall off from the O-ring sealing groove. When the second outer ring 9 and the first outer ring 4 are put together, the first O-ring 13 and the second O-ring 14 are easy to be sheared, and the sealing effect is not achieved. Summary of the Invention

[0007] The purpose of the present invention is to provide an assembly method for a three-row roller pitch bearing with negative clearance, so as to solve the problems faced by such bearings during the assembly process.

[0008] To achieve the above-mentioned object, the technical solution adopted by the present invention is: an assembly method of a negative clearance three-row roller pitch bearing, wherein the negative clearance three-row roller pitch bearing comprises an inner ring, a first outer ring, and a second outer ring, wherein the first outer ring and the second outer ring have a large end and a small end in the axial direction, respectively, and radial raceways are provided on the inner ring and the first outer ring. The method comprises the following steps:

[0009] Step 1: determining a target thermal expansion of the first outer ring based on the radial clearance of the bearing;

[0010] Step 2: Place the large end face of the first outer ring downward on multiple supports of equal height, and wrap a heating tape around the outer circumference of the first outer ring. Place multiple dial indicators near the radial raceway inside the first outer ring so that the probes of the dial indicators are in contact with the radial raceway. Then, heat the first outer ring with the heating tape, and regularly observe the needle readings of the dial indicators. Calculate the heating expansion Δd of the first outer ring based on the change in the needle readings of the dial indicators. Δd is equal to twice the average of the changes in the needle readings of the multiple dial indicators.

[0011] Step 3: During the heating process, the radial rollers and the radial cage are adhered to the radial raceway of the inner ring by grease;

[0012] Step 4: When the heating expansion Δd of the first outer ring reaches the target heating expansion range determined in Step 1, stop heating and quickly assemble the first axial roller and the first axial cage on the first axial raceway of the first outer ring;

[0013] Step 5: Smoothly hoist the inner ring of the radial roller and radial cage installed in step 3 into the first outer ring;

[0014] Step 6: Install the second axial roller and the second axial retainer into the second axial raceway of the second outer ring;

[0015] Step 7: Apply an appropriate amount of grease to the sealing groove on the small end face of the second outer ring, and then install the O-ring into the corresponding sealing groove;

[0016] Step 8: Lift the second outer ring with the small end facing downwards and place it steadily on the small end of the first outer ring;

[0017] Step 9: Use screws to connect the first outer ring and the second outer ring together;

[0018] Step 10: Install the second sealing ring at the ends of the second outer ring and the inner ring, then turn the bearing over and install the first sealing ring at the ends of the first outer ring and the inner ring to complete the assembly of the bearing.

[0019] In step 2, the dial indicator is installed on a magnetic base, and the magnetic base is adsorbed on a corresponding equal-height support.

[0020] In step two, the plurality of dial gauges are uniformly spaced in the circumferential direction.

[0021] In step two, after the measuring head of the dial gauge contacts the radial raceway of the bearing outer ring, the dial gauge is ensured to have a needle indication of no less than 3mm, and the dial gauge dial is rotated so that the dial gauge needle is indicated at the zero position on the dial. During the monitoring of the dial gauge, the needle indication is the amount of change in the needle indication.

[0022] In step two, the range of the dial gauge is no less than 5mm.

[0023] In step two, the heating temperature of the heating band is set to a maximum of 100℃.

[0024] In step two, when the indication of at least one of the plurality of dial gauges reaches or exceeds half of the target heating expansion amount, the heating expansion amount Δd at this time is recorded and calculated. When the indications of the plurality of dial gauges are all lower than half of the target heating expansion amount, the indications do not need to be recorded and calculated.

[0025] The grease used in steps three and seven is the same as the grease required to be filled in the bearing.

[0026] In step nine, the screw is tightened in a cross-shaped tightening manner, and is tightened to the required tightening torque of the screw in three times.

[0027] The clearance between the abutting surfaces of the first outer ring and the second outer ring is detected by using a feeler gauge during the screw tightening process.

[0028] The beneficial effects of the present application are as follows: 1. The present application uses a heating band to heat the first outer ring, so as to facilitate the smooth installation of the inner ring, radial rollers and radial retainers. The heating band heating form can be carried out on the bearing assembly site, and the heating can be quickly carried out immediately after heating, without lifting the first outer ring. Therefore, the situation that the first outer ring cannot be assembled due to the small cooling expansion amount caused by the instability of the first outer ring due to long lifting time can be avoided.

[0029] 2. After the heating band is heated in the present application, personnel do not need to enter and exit the heating furnace to lift the heated outer ring, thereby ensuring the physical health and safety of the operators.

[0030] 3. The present application uses a plurality of dial gauges to monitor the heating expansion amount of the first outer ring in real time, thereby avoiding the problem that the operators are easily scalded when entering and exiting the first outer ring for measurement multiple times, and ensuring safe production. Moreover, the change in the expansion amount is monitored in real time by using the dial gauge, the measurement process is simple, and the temperature of the first outer ring does not need to be measured.

[0031] 4. In the assembly process of the present application, the radial rollers and radial retainers are coated with lubricating grease, which will not fall out from the inner ring radial raceway; the two O-shaped sealing rings on the end face of the first outer ring are coated with lubricating grease, which will not fall off from the sealing groove. Therefore, the assembly process is ensured to proceed smoothly. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0033] Figure 1 Structure diagram of the negative clearance three-row roller variable pitch bearing described in the present application;

[0034] Figure 2 When the negative clearance three-row roller variable pitch bearing described in the present application is assembled, the first outer ring is heated and the expansion amount is measured.

[0035] Figure 3 is a top view; Figure 2

[0036] Marked in the figure: 1-inner ring, 2-first sealing ring, 3-first axial roller, 4-first outer ring, 5-first axial retainer, 6-radial retainer, 7-radial roller, 8-screw, 9-second outer ring, 10-second axial roller, 11-second axial retainer, 12-second sealing ring, 13-first O-shaped sealing ring, 14-second O-shaped sealing ring, 15-heating belt, 16-equal-height support, 17-magnetic table seat, 18-dial indicator. DETAILED DESCRIPTION

[0037] The present application will be further described in detail below in combination with the drawings and embodiments, but it is not used as any limitation on the application.

[0038] The negative clearance three-row roller variable pitch bearing described in the present application is a conventional bearing in the art, in order to facilitate the description of its assembly method, the following will be combined with the drawings to describe the assembly method of the negative clearance three-row roller variable pitch bearing. Figure 1 ​Briefly describe its structure. The bearing includes inner ring 1, first axial roller 3, first outer ring 4, first axial cage 5, radial cage 6, radial roller 7, second outer ring 9, second axial roller 10, second axial cage 11 and sealing ring. The two ends of the first outer ring 4 and the second outer ring 9 in the axial direction are respectively large end and small end, and are assembled in the outer ring 1 with the small end opposite; the inner ring 1 and the first outer ring 4 and the inner ring 1 and the second outer ring 9 are respectively provided with first axial raceway and second axial raceway, the first axial roller 3 and the first axial cage 5 are assembled on the first axial raceway, the second axial roller 10 and the second axial cage 11 are assembled on the second axial raceway; the inner ring 1 and the first outer ring 4 are provided with radial raceway, the radial raceway is located between the first axial raceway and the second axial raceway, the radial roller 7 and the radial cage 6 are assembled on the radial raceway. The sealing ring includes first sealing ring 2, second sealing ring 12, first O-shaped sealing ring 13 and second O-shaped sealing ring 14. The first sealing ring 2 is installed at the axial end of the inner ring 1 and the first outer ring 4, the second sealing ring 12 is installed at the other axial end of the inner ring 1 and the second outer ring 9, the first O-shaped sealing ring 13 and the second O-shaped sealing ring 14 are arranged between the end faces of the first outer ring 4 and the second outer ring 9, for example, two concentric annular sealing grooves can be arranged on the small end face of the second outer ring 9, which respectively accommodate the first O-shaped sealing ring 13 and the second O-shaped sealing ring 14. The first outer ring 4 and the second outer ring 9 are fixedly connected through the screw 8.

[0039] The specification parameters of the three-row roller variable pitch bearing described in the embodiment are as follows: the outer diameter of the outer ring is φ3215mm, the inner diameter of the inner ring is φ2690mm, the assembly height is 320mm, the finished product weight is 5220kg, the radial clearance is-0.20mm; the cage material is POM, the O-shaped sealing ring material is butyronitrile rubber, and the using temperature of the cage and the O-shaped sealing ring is not more than 100℃.

[0040] On the basis of the above structure, the assembly method of the negative clearance three-row roller variable pitch bearing is described in detail, which comprises the following steps:

[0041] Step one, calculate the target heating expansion amount required by the first outer ring 4, the heating temperature is highest 100℃, the temperature of the first outer ring 4 before heating is the environmental temperature, which is 20℃, the radial raceway of the first outer ring 4 is φ3032mm, the heating expansion amount Δd=10 -6 ×3032×(100-20)=2.5mm, which is greater than the absolute value of the radial clearance-0.20mm, so the target heating expansion amount of the first outer ring 4 is set to 2mm-2.5mm.

[0042] Step two, as Figure 2 , 3As shown, the large end face of the first outer ring 4 is placed downward on three equal-height supports 16, and a heating belt 15 is wrapped around the outer circular face of the first outer ring 4, three sets of dial gauges 18 are placed at the radial raceways of the first outer ring 4 for real-time monitoring of the heating expansion of the radial raceways during the heating process; then the power supply of the heating belt 15 is turned on, the heating temperature is set to a maximum of 100℃, the heating of the first outer ring 4 is started, and the readings of the dial gauges 18 are observed at regular intervals.

[0043] Step three, during the heating process in step two, an appropriate amount of lubricating grease is applied to the radial raceways of the inner ring 1 and the radial rollers 7 and radial retainers 6, so that the radial rollers 7 and radial retainers 6 are adhered to the radial raceways of the inner ring 1, and the brand of the applied lubricating grease should be the same as the brand of the lubricating grease required to be filled in the bearing.

[0044] Step four, when the heating expansion monitored by the dial gauges 18 reaches the target heating expansion, the first axial roller 3 and the first axial retainer 5 are placed beside the first outer ring 4, and then the inner ring 1 with the radial rollers 7 and radial retainers 6 assembled is hoisted above the first outer ring 4;

[0045] The power supply of the heating belt 15 is turned off, and the first axial roller 3 and the first axial retainer 5 are quickly assembled on the first axial raceway of the first outer ring 4.

[0046] To prevent the assembly of the first axial roller 3 and the first axial retainer 5 for too long, causing the temperature of the first outer ring 4 to decrease and the size of the radial raceway to shrink, 4-5 people should be arranged to simultaneously assemble the first axial roller 3 and the first axial retainer 5 to shorten the assembly time.

[0047] Step five, the inner ring 1 with the radial rollers 7 and radial retainers 6 assembled is assembled into the first outer ring 4, and the lowering process of the overhead crane should be smooth and cannot be suddenly lowered or stopped to prevent the radial rollers 7 and radial retainers 6 from being dropped.

[0048] Step six, the second axial roller 10 and the second axial retainer 11 are assembled into the second axial raceway of the second outer ring 9.

[0049] Step seven, an appropriate amount of lubricating grease is applied to the sealing groove on the small end face of the second outer ring 9, and then the first O-shaped sealing ring 13 and the second O-shaped sealing ring 14 are assembled into the corresponding sealing grooves, and the brand of the applied lubricating grease should be the same as the brand of the lubricating grease required to be filled in the bearing.

[0050] Step eight, the second outer ring 9 with the small end face downward is lifted by the overhead crane, and after the connecting screw holes of the second outer ring 9 and the connecting screw holes of the first outer ring 4 are aligned, the second outer ring 9 is smoothly placed on the small end face of the first outer ring 4. The lowering process of the overhead crane should be smooth and cannot be suddenly lowered or stopped to prevent the first O-shaped sealing ring 13 and the second O-shaped sealing ring 14 from being dropped.

[0051] Step nine, put the connecting screw 8 into the connecting screw hole of the second outer ring 9, and tighten it with the connecting screw hole of the first outer ring 4.

[0052] The screw 8 is tightened in a cross-shaped tightening manner, and is tightened to the required tightening torque of the screw in three times. During the tightening process, the gap between the abutting surfaces of the first outer ring 4 and the second outer ring 9 is detected by using a feeler gauge to ensure that the 0.05mm feeler gauge does not enter.

[0053] Step ten, the second sealing ring 12 is installed at the end of the second outer ring 9 and the inner ring 1, and then the bearing is turned over by the crown block, the first sealing ring 2 is installed at the end of the first outer ring 4 and the inner ring 1, and the assembly of the bearing is completed.

[0054] After the assembly is completed, the identification is made according to the drawing requirements, the assembly nameplate is installed, and the finished product is packaged with packaging materials after passing the product inspection, and the outer label is pasted.

[0055] Further, in the step two, three dial gauges 18 are used in the embodiment, and the range of the dial gauges 18 is not less than 5mm, and the three dial gauges 18 are uniformly arranged along the circumference. When the dial gauges 18 are installed, the dial gauges 18 are installed on the magnetic table seat 17, the magnetic table seat 17 is adsorbed on the equal-height support 16, and the position of the dial gauges 18 is adjusted to make the measuring head of the dial gauges 18 contact with the radial raceway of the first outer ring 4.

[0056] Further, after the measuring head of the dial gauges 18 contacts with the radial raceway of the first outer ring 4, it is ensured that the pointer indication of the dial gauges 18 is not less than 3mm, and the dial ring of the dial gauges 18 is rotated to make the pointer indication of the dial gauges 18 at the zero position of the dial, so that the pointer indication of the dial gauge is the change amount of the pointer indication in the observation, and there is no need for conversion, which can simplify the observation process.

[0057] The heating expansion amount Δd of the first outer ring 4 can be calculated according to the change amount of the pointer indication of the dial gauges 18, and Δd=2×(A1+A2+A3)÷3, wherein A1, A2 and A3 are the change amounts of the pointer indications of the three dial gauges 18 respectively. According to the previous calculation, the target heating expansion amount of the first outer ring 4 in the embodiment is 2mm~2.5mm, so the average of the indications of the three dial gauges 18 needs to be greater than or equal to 1mm~1.25mm. In the observation process, when the indication of the dial gauge reaches or exceeds 1~1.25mm, the reading needs to be read and recorded, and the heating expansion amount Δd at this time is calculated; when the indications of the three dial gauges 18 are all less than 1mm, the average cannot be greater than or equal to 1mm~1.25mm, so at this time, there is no need for recording and calculation.

[0058] In this embodiment, three dial indicators 18 are used for testing, and the arithmetic mean of the measurement results is taken to reduce detection errors. In other embodiments, the number of dial indicators 18 can be greater than three, further reducing measurement errors and improving measurement accuracy. When the number of dial indicators 18 is n, Δd = 2 × (A1 + A2 + ... + An) ÷ n, where n is a natural number greater than or equal to 3, and An is the change in the needle indication of the nth dial indicator, i.e., the needle indication.

[0059] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Those skilled in the art should understand that the specific implementation methods of the present invention can be modified or replaced with equivalents with reference to the above embodiments. Any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention are within the scope of protection of the pending claims.

Claims

1. A method for assembling a negative clearance three-row roller pitch bearing, wherein the negative clearance three-row roller pitch bearing comprises an inner ring, a first outer ring, and a second outer ring, wherein the first outer ring and the second outer ring have a large end and a small end in the axial direction, respectively, and radial raceways are provided on the inner ring and the first outer ring, characterized in that: The method comprises the following steps: Step 1: determining a target thermal expansion of the first outer ring based on the radial clearance of the bearing; Step 2: Place the large end face of the first outer ring downward on multiple supports of equal height, and wrap a heating tape around the outer circumference of the first outer ring. Place multiple dial indicators near the radial raceway inside the first outer ring so that the probes of the dial indicators are in contact with the radial raceway. Then, heat the first outer ring with the heating tape, and regularly observe the needle readings of the dial indicators. Calculate the heating expansion Δd of the first outer ring based on the change in the needle readings of the dial indicators. Δd is equal to twice the average of the changes in the needle readings of the multiple dial indicators. Step 3: During the heating process, the radial rollers and the radial cage are adhered to the radial raceway of the inner ring by grease; Step 4: When the heating expansion Δd of the first outer ring reaches the target heating expansion range determined in Step 1, stop heating and quickly assemble the first axial roller and the first axial cage on the first axial raceway of the first outer ring; Step 5: Smoothly hoist the inner ring of the radial roller and radial cage installed in step 3 into the first outer ring; Step 6: Install the second axial roller and the second axial retainer into the second axial raceway of the second outer ring; Step 7: Apply an appropriate amount of grease to the sealing groove on the small end face of the second outer ring, and then install the O-ring into the corresponding sealing groove; Step 8: Lift the second outer ring with the small end facing downwards and place it steadily on the small end of the first outer ring; Step 9: Use screws to connect the first outer ring and the second outer ring together; Step 10: Install the second sealing ring at the ends of the second outer ring and the inner ring, then turn the bearing over and install the first sealing ring at the ends of the first outer ring and the inner ring to complete the assembly of the bearing.

2. The assembly method of the negative clearance three-row roller pitch bearing according to claim 1, characterized in that: In step 2, the dial indicator is installed on a magnetic base, and the magnetic base is adsorbed on a corresponding equal-height support.

3. The assembly method of the negative clearance three-row roller pitch bearing according to claim 1, characterized in that: In step 2, the plurality of dial indicators are evenly spaced along the circumferential direction.

4. The method for assembling a negative clearance three-row roller pitch bearing according to claim 1, characterized in that: In step 2, after the probe of the dial indicator contacts the radial raceway of the bearing outer ring, ensure that the needle indication of the dial indicator is not less than 3 mm, and rotate the dial indicator bezel so that the needle of the dial indicator indicates the zero position of the dial. During the monitoring process of the dial indicator, the needle indication is the change in the needle indication.

5. The assembly method of the negative clearance three-row roller pitch bearing according to claim 1, characterized in that: In step 2, the measuring range of the dial indicator is not less than 5 mm.

6. The method for assembling a negative clearance three-row roller pitch bearing according to claim 1, characterized in that: In step 2, the heating temperature of the heating belt is set to a maximum of 100°C.

7. The assembly method of the negative clearance three-row roller pitch bearing according to claim 1, characterized in that: In step 2, when the indication of at least one of the multiple dial indicators reaches or exceeds half of the target heating expansion, the heating expansion Δd at this time is recorded and calculated. When the indications of the multiple dial indicators are all lower than half of the target heating expansion, there is no need to record and calculate the indication.

8. The assembly method of the negative clearance three-row roller pitch bearing according to claim 1, characterized in that: The grease brand used in steps 3 and 7 is the same as the grease brand required to be added to the bearing.

9. The method for assembling a negative clearance three-row roller pitch bearing according to claim 1, characterized in that: In step nine, the screws are tightened in a Pozidriv manner and tightened three times to the required tightening torque of the screws.

10. The assembly method of the negative clearance three-row roller pitch bearing according to claim 9, characterized in that: During the screw tightening process, use a feeler gauge to detect the gap between the fitting surfaces of the first outer ring and the second outer ring.

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